Interleukin-6 Receptor Antibody Research Articles

Tocilizumab-induced erythroderma

Auteur(s) : Motonobu Nakamura, Yoshiki Tokura Department of Dermatology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan Tocilizumab is a humanized anti-human interleukin 6 receptor (IL-6R) antibody, engineered by grafting the complementarily determining regions of a mouse anti-human IL-6R antibody into human IgG1 to create a human antibody with a human IL-6R binding site [1, 2]. Tocilizumab binds to the IL-6 binding [...]

Evidence for the role of Th17 cell inhibition in the prevention of autoimmune diseases by anti‐interluekin‐6 receptor antibody

Deregulated production of interleukin-6 (IL-6) has been found in several chronic inflammatory autoimmune disorders, including rheumatoid arthritis (RA) and inflammatory bowel diseases. Treatment with tocilizumab, a humanized anti-human IL-6 receptor (IL-6R) antibody, significantly improved disease activity and inhibited the progression of joint destruction in RA patients, but the reason why IL-6 blockade causes improvement of RA is still unclear. In this review, we discuss the influence of anti-IL-6R antibody treatment on the differentiation of Th17 cells, which are thought to be involved in the pathogenesis of autoimmune diseases in animal models, present new results for the effect of anti-IL-6R antibody on the induction of Th17 cells in a mouse collagen-induced arthritis model, and come to the conclusion that anti-IL-6R antibody inhibited the differentiation of Th17 cells in mouse models. It is thought that this inhibitory action may contribute to the therapeutic effects of anti-IL-6R antibody in human autoimmune diseases.

Effects of interleukin-6 blockade on the development of autoimmune thyroiditis in nonobese diabetic mice

We explored the role of interleukin-6 (IL-6) in the development of autoimmune thyroiditis in nonobese diabetic (NOD) mice, an animal model of Hashimoto's thyroiditis, using anti-mouse IL-6 receptor antibody (MR16-1). Thyroiditis was induced by iodide ingestion or mouse thyroglobulin (Tg) immunization. Mice were injected intraperitoneally with saline, control rat IgG, or MR16-1 (2 or 8 mg). Iodide ingestion did not increase serum IL-6 levels and MR16-1 (2 mg) failed to prevent the development of thyroiditis. In contrast, Tg immunization induced a rapid and significant increase in serum IL-6 levels. While MR16-1 (2 mg) had no effect on Tg-induced thyroiditis, the severity, but not incidence, of thyroiditis was reduced in 8 mg MR16-1-treated mice compared with saline-injected mice. However, thyroiditis development in the 8 mg MR16-1-treated mice was indistinguishable from that in the control IgG-treated mice. MR16-1 (8 mg) did not affect serum anti-Tg antibody levels. These results suggest that IL-6 may play only a minor role in the development of autoimmune thyroiditis in NOD mice.

Novel models of cancer-related anemia in mice inoculated with IL-6-producing tumor cells

We established models of cancer-related anemia in mice from subcutaneous inoculation of two IL-6-producing cancer cell lines, human lung cancer cell line LC-06-JCK and murine colon26 clone 5 colon cancer cells. In both models, elevated levels of IL-6 were detected in sera and hemoglobin levels significantly decreased compared with non-tumor-bearing mice. In the LC-06-JCK model, serum albumin levels also decreased with elevated levels of human IL-6 in sera. On the other hand, serum levels of EPO increased, although anemia developed and did not improve. The development of cancer-related anemia was prevented by the administration of a rat anti-mouse IL-6 receptor antibody, MR16-1, in the LC-06-JCK model. It is therefore suggested that IL-6 causes anemia independent of a reduction in EPO levels. Our preclinical models should be useful for exploring new modalities for the treatment of cancer-related anemia.

Leukoencephalopathy with Cognitive Impairment following Tocilizumab for the Treatment of Rheumatoid Arthritis (RA)

The biological agent tocilizumab, is a humanized, anti-human interleukin-6 receptor antibody. A 72-year-old woman developed cognitive impairment during the Phase III clinical trial of tocilizumab for the treatment of rheumatoid arthritis. MRI demonstrated hyperintense dissemination throughout the white matter on T2WI. An initial diagnosis of possible progressive multifocal leukoencephalopathy was made, but the PCR for JC virus DNA was negative in the CSF. The leukoencephalopathy might have been caused by a mechanism related to tocilizumab itself. It is strongly recommended to perform MRI if a patient develops any cognitive impairment during tocilizumab therapy.

Mechanisms and pathologic significances in increase in serum interleukin-6 (IL-6) and soluble IL-6 receptor after administration of an anti–IL-6 receptor antibody, tocilizumab, in patients with rheumatoid arthritis and Castleman disease

AbstractInterleukin-6 (IL-6) plays pathologic roles in immune-inflammatory diseases such as rheumatoid arthritis (RA) and Castleman disease. By inhibiting IL-6 receptors (IL-6Rs), tocilizumab (a humanized anti–IL-6R antibody) ameliorates the symptoms of these diseases and normalizes acute-phase proteins, including C-reactive protein (CRP). We found that tocilizumab treatment increased serum levels of IL-6 and soluble IL-6R (sIL-6R). To investigate the pathologic significance of these increases, we analyzed the kinetics of serum IL-6 and sIL-6R and the proportion of sIL-6R saturated with tocilizumab after tocilizumab administration in patients with RA and Castleman disease and then compared the results with the CRP values. Serum IL-6 and sIL-6R markedly increased after tocilizumab administration in both RA and Castleman disease. As long as free tocilizumab was detectable, sIL-6R was saturated with tocilizumab and IL-6 signaling was completely inhibited. We concluded that it is likely that sIL-6R increased because its elimination half-life was prolonged by the formation of tocilizumab/sIL-6R immune complex, and that free serum IL-6 increased because IL-6R–mediated consumption of IL-6 was inhibited by the unavailability of tocilizumab-free IL-6R. We also concluded that the increased level of free IL-6 during tocilizumab treatment closely reflects the actual endogenous IL-6 production and true disease activity.

Costimulation with angiotensin II and interleukin 6 augments angiotensinogen expression in cultured human renal proximal tubular cells

Augmented intrarenal ANG II stimulates IL-6, which contributes to renal injury. The expression of intrarenal angiotensinogen (AGT) is enhanced by increased intrarenal ANG II in human renin/human AGT double transgenic mice. ANG II also augments AGT expression in hepatocytes and cardiac myocytes. However, the mechanisms underlying AGT augmentation by ANG II and the contribution of IL-6 to this system are poorly understood. This study was performed in human renal proximal tubular epithelial cells (HRPTECs) to test the hypothesis that IL-6 contributes to the upregulation of AGT expression by ANG II. Human kidney-2 (HK-2) cells, immortalized HRPTECs, were incubated with 10(-7) M ANG II and/or 10 ng/ml IL-6 for up to 24 h. AGT mRNA and protein expressions were measured by real-time RT-PCR and ELISA, respectively. The activities of NF-kappaB and STAT3 were evaluated by Western blotting and EMSA. Stimulation with either ANG II or IL-6 did not significantly alter AGT mRNA or protein expression. In contrast, costimulation with ANG II and IL-6 significantly increased AGT mRNA and protein expressions (1.26 +/- 0.10 and 1.16 +/- 0.13 over control, respectively). Olmesartan, an ANG II type 1 receptor blocker, and an IL-6 receptor antibody individually inhibited this synergistic effect. NF-kappaB was also activated by costimulation with ANG II and IL-6. Phosphorylation and activity of STAT3 were increased by stimulation with IL-6 alone and by costimulation. The present study indicates that IL-6 plays an important role in ANG II-mediated augmentation of AGT expression in human renal proximal tubular cells.

The recombinant humanized anti-IL-6 receptor antibody tocilizumab, an innovative drug for the treatment of rheumatoid arthritis

Background: IL-6 is a pro-inflammatory cytokine with multiple roles in the pathogenesis of rheumatoid arthritis (RA). Targeting IL-6 with the humanized anti IL-6 receptor antibody tocilizumab was effective in several placebo-controlled clinical studies in RA. Objectives: To address how clinically efficacious blockade of IL-6 signalling with inteleukin-6 receptor antibody is in RA patients and what the potential mode of action explaining tocilizumab activity in RA treatment could be. Results/conclusion: IL-6 induces autoantibody-producing plasma cells and effector T cells and is implicated in the development of clinical signs and symptoms, including increased synthesis of acute phase reactants, fatigue, anaemia and anorexia. Its effects also included significant improvements in American College of Rheumatology (ACR)20, ACR50 and ACR70 values, as well as in health-related quality of life measures, compared with controls. Tocilizumab also prevents radiographic progression of joint damage. Tocilizumab is generally well tolerated and efficacious in patients refractive to conventional DMARD therapies.

Review of tocilizumab in the treatment of rheumatoid arthritis.

Constitutively overproduced in proliferating synovial tissues, interleukin-6 (IL-6) is deeply involved in the pathology of rheumatoid arthritis (RA). Tocilizumab is a humanized anti-human IL-6 receptor antibody that binds to soluble and membrane-bound IL-6 receptor, and at detectable levels in blood, tocilizumab is capable of almost completely blocking the transmembrane signaling of IL-6. In clinical trials for patients with RA in Japan, tocilizumab monotherapy has shown clinical efficacy equaling that of tumor necrosis factor (TNF) inhibitor in combination with methotrexate, and in an extension study in patients who responded to tocilizumab, almost no patients showed a decrease in the efficacy of tocilizumab. Evidence obtained in a phase III study in Japan demonstrated that tocilizumab monotherapy had a sig-nificant inhibitory effect on the progression of structural joint damage compared with that of conventional disease modifying antirheumatic drugs (DMARDs). Furthermore it has been shown that tocilizumab has an excellent ability to suppress serum amyloid A levels and could therefore be an important therapeutic strategy in amyloid A amyloidosis secondary to rheumatic diseases. The safety profile of tocilizumab appears to be satisfactory. However, several serious infections were also reported, and careful monitoring is therefore important during use.

Tocilizumab for the treatment of rheumatoid arthritis

Tocilizumab is a humanized anti-human IL-6 receptor antibody that specifically inhibits the biological activity of IL-6 by competitively inhibiting the binding of IL-6 to the IL-6 receptor. Clinical trials have shown that tocilizumab 8 mg/kg administered by monthly infusion not only improves clinical signs and symptoms of refractory rheumatoid arthritis but also suppresses radiographic progression. In regard to safety, the most common adverse event was nonsevere infection, such as nasopharyngitis, although the incident rate of adverse events was slightly higher than that of disease-modifying antirheumatic drug treatment. Studies have shown that there is no specific infection or prolongation of infection related to tocilizumab treatment. Tocilizumab is a promising therapeutic agent with statisfactory efficacy and safety for rheumatoid arthritis.

Pathogenic analysis of chronic inflammatory disease based on the clinical results by IL-6 blocking therapy

Every clinician knows the elevation of acute phase proteins at the inflammatory status, but nobody knows the CRP or SAA induction mechanism on inflammation, in which a lot of cytokines or chemokines are activated. Induction mechanism of CRP and SAA is analyzed based on the result of the normalization of serum CRP or SAA in rheumatoid arthritis by the IL-6 blocking therapy with a humanized anti IL-6 receptor antibody. Ultimately, IL-6 is a pivotal cytokine among IL-6, IL-1 and TNF-a in induction of CRP and SAA in hepatocyte. Furthermore, activation of STAT3, a transcriptional factor under IL-6 signal transduction pathway, is critical on the expression of these mRNAs. Based on this mechanism, the depression of CRP and SAA induction could be explained by the IL-6 blockage both in vitro and in vivo. Therefore, IL-6 blocking therapy may elucidate the pathogenic significance of IL-6 in chronic inflammatory disease.

Clinical benefits of anti-human IL-6 receptor antibody therapy

Interleukin-6 (IL-6) plays pathological roles in promoting autoimmune reactions and chronic inflammation as well as destruction of bone and cartilage in rheumatoid arthritis (RA). Humanized anti-human IL-6 receptor antibody, tocilizumab, specifically recognizes human IL-6 receptor and inhibits IL-6 actions. Tocilizumab has been shown to ameliorate the disease activity of RA in the clinical trials. Tocilizuamb can be a new therapy based on the pathology of RA.

Recent Advances in Immunopathophysiology of Interleukin-6: An Innovative Therapeutic Drug, Tocilizumab (Recombinant Humanized Anti-human Interleukin-6 Receptor Antibody), Unveils The Mysterious Etiology of Immune-Mediated Inflammatory Diseases

Interleukin (IL)-6 cDNA was originally cloned as a terminal B cell differentiation factor into antibody-producing plasma cells. This revealed that it is a multifunctional cytokine that acts on a variety of cells. From the clinical viewpoint, it is especially important that IL-6 acts on hepatocytes to induce acute-phase reactants, including C-reactive protein, serum amyloid A protein, and fibrinogen, and to decrease serum albumin levels. Very recently, this cytokine has been found to enhance the synthesis of a peptide called hepcidin in the liver which regulates iron recycling, resulting in anemia due to hypofferemia. It has also been shown that IL-6 is responsible for various clinical symptoms, including the appearance of autoantibodies, fatigue, anemia, anorexia, fever, and increases in the erythrocyte sedimentation rate, all of which develop in patients with various chronic autoimmune inflammatory diseases. In practice, blocking the IL-6 signaling pathway with a recombinant humanized anti-IL-6 receptor antibody, tocilizumab (TCZ), has dramatically improved all the signs and symptoms of these patients. A study in mice demonstrated that IL-6 promotes the development of a new type of T-helper cells called Th17 cells that impact the pathogenesis of autoimmune diseases. This suggests that TCZ is not only an antiinflammatory agent but also might affect basic autoimmunity. In this review, recent advances in the immunobiology of interleukin-6 related to immune-mediated diseases are discussed.

An Innovative Therapeutic Drug, Tocilizumab (Recombinant Humanized Anti-human Interleukin-6 Receptor Antibody) Unveils the Mysterious Etiology of Immune-mediated Inflammatory Diseases

An Innovative Therapeutic Drug, Tocilizumab (Recombinant Humanized Anti-human Interleukin-6 Receptor Antibody) Unveils the Mysterious Etiology of Immune-mediated Inflammatory Diseases

Anti-rat soluble IL-6 receptor antibody down-regulates cardiac IL-6 and improves cardiac function following trauma–hemorrhage

Although anti-IL-6-mAb down-regulates cardiac IL-6 and attenuates IL-6-mediated cardiac dysfunction following trauma–hemorrhage, it is not known whether blockade of IL-6 receptor will down-regulate cardiac IL-6 and improve cardiac function under those conditions. Six groups of male adult rats (275–325 g) were used: sham/trauma–hemorrhage + vehicle, sham/trauma–hemorrhage + IgG, sham/trauma–hemorrhage + anti-rat sIL-6R. Rats underwent trauma–hemorrhage (removal of 60% of the circulating blood volume and fluid resuscitation after 90 min). Vehicle (V), normal goat IgG or anti-rat sIL-6R (16.7 μg/kg BW) was administered intra-peritoneally in the middle of resuscitation. Two hours later, cardiac function was measured by ICG dilution technique; blood samples collected, cardiomyocytes isolated, and cardiomyocyte nuclei were then extracted. Cardiac IL-6, IL-6R, gp130, IκB-α/P-IκB-α, NF-κB, and ICAM-1 expressions were measured by immunoblotting. Plasma IL-6 and cardiomyocyte NF-κB DNA-binding activity were determined by ELISA. In additional animals, heart harvested and cardiac MPO activity and CINC-1 and -3 were also measured. In another group of rats, cardiac function was measure by microspheres at 24 h following trauma–hemorrhage. Cardiac function was depressed and cardiac IL-6, P-IκB-α, NF-κB and its DNA-binding activity, ICAM-1, MPO activity, and CINC-1 and -3 were markedly increased after trauma–hemorrhage. Moreover, cardiac dysfunction was evident even 24 h after trauma–hemorrhage. Administration of sIL-6R following trauma–hemorrhage: (1) improved cardiac output at 2 h and 24 h ( p < 0.05); (2) down-regulated both cardiac IL-6 and IL-6R ( p < 0.05); and (3) attenuated cardiac P-IκB-α, NF-κB, NF-κB DNA-binding activity, ICAM-1, CINC-1, -3, and MPO activity ( p < 0.05). IgG did not significantly influence the above parameters. Thus, IL-6-mediated up-regulation of cardiac NF-κB, ICAM-1, CINC-1, -3, and MPO activity likely contributes to altered cardiac function following trauma–hemorrhage. Since IL-6R blockade after trauma–hemorrhage down-regulates cardiac IL-6 and improves cardiac functions, blockade of IL-6R following trauma–hemorrhage appears to be a novel and effective adjunct for improving organ and cell function under those conditions.

Renal Involvement in Multicentric Castleman Disease With Glomeruloid Hemangioma of Skin and Plasmacytoma

A 47-year-old man presented with fever of unknown origin, generalized weakness, edema, and renal failure. He had left-sided pleural effusion, generalized lymphadenopathy, multiple nontender cutaneous nodules, hepatomegaly, renal failure, and hypergammaglobulinemia. Axillary lymph node biopsy showed findings consistent with Castleman disease of the hyaline vascular type associated with interfollicular plasmacytosis. A renal biopsy performed in view of proteinuria and acute renal failure showed hypercellular glomeruli with capillary loop thickening and double contours consistent with membranoproliferative glomerulonephritis. Skin nodule biopsy showed a glomeruloid hemangioma characterized by dermal proliferation of capillary loops in a nodular manner resembling a glomerulus. He experienced clinical and biochemical remission with steroids. Discontinuation of steroid therapy was associated with recurrence of renal failure, reappearance of nodules, lymphadenopathy, and appearance of bony lytic lesions. Biopsy of bony lytic lesions showed plasmacytoma. The patient achieved complete remission on treatment with steroids and cyclophosphamide and is free of symptoms at the end of 40 months of follow-up. To our knowledge, this is the first case report of the occurrence of membranoproliferative glomerulonephritis, glomeruloid hemangioma of the skin, and plasmacytoma in a patient with multicentric Castleman disease without human immunodeficiency virus infection.

Humanized anti–interleukin-6 receptor antibody treatment of multicentric Castleman disease

AbstractMulticentric Castleman disease (MCD) is an atypical lymphoproliferative disorder characterized by systemic lymphadenopathy and constitutional inflammatory symptoms. Dysregulated overproduction of interleukin-6 is responsible for the clinical abnormalities. This multicenter prospective study was undertaken to evaluate the safety and efficacy of a humanized anti–human interleukin-6 (IL-6) receptor monoclonal antibody (MRA) in patients with MCD. We report here results of the first 60 weeks of the study enrolling 28 patients. The initial dosing period consisted of 8 infusions of 8 mg/kg MRA administered biweekly. Adjustments in the dose and treatment interval were allowed for each patient in an extension phase after 16 weeks. Within 16 weeks, treatment with MRA consistently alleviated lymphadenopathy and all the inflammatory parameters. Hemoglobin, albumin, and total cholesterol levels, high-density lipoprotein cholesterol values, and body mass index all increased significantly. In addition, fatigue diminished. Chronic inflammatory symptoms were successfully managed over 60 weeks. In 8 (28.6%) patients, the MRA dose was decreased or the treatment interval was extended without exacerbation. Eleven (73.3%) of 15 patients who had received oral corticosteroids before study entry were able to do well on a reduced corticosteroid dose. Most adverse events were mild to moderate in severity. MRA was tolerated well and significantly alleviated chronic inflammatory symptoms and wasting in patients with MCD.

Expression and functional characterization of killer whale ( Orcinus orca) interleukin-6 (IL-6) and development of a competitive immunoassay

Interleukin-6 (IL-6) is a cytokine that can reach detectable systemic levels and is a major inducer of the acute phase response. As such, clinical assays to identify this cytokine in mammalian sera are of diagnostic value. A 558 base-pair (bp) fragment of killer whale IL-6 was cloned and expressed as a 21 kDa protein in Escherichia coli. Biological activity of the recombinant killer whale IL-6 (rkwIL-6) was demonstrated using the IL-6-dependent B9 mouse hybridoma cell line; acute phase sera from a killer whale and supernatants from lipopolysaccharide (LPS)-stimulated killer whale peripheral blood mononuclear cells (PBMCs) also supported the proliferation of the B9 hybridoma. Rat anti-mouse IL-6 receptor antibody effectively blocked biological activity of all three sources of IL-6. Polyclonal antisera, specific for the recombinant protein, were obtained by successive immunization of a rabbit with rkwIL-6. The polyclonal antibody was capable of neutralizing the biological activity of both recombinant and native kwIL-6. A competitive enzyme-linked immunosorbent assay (ELISA) was developed using the polyclonal rabbit anti-rkwIL-6 and the recombinant protein; sensitivity of the assay was in the range of 1 ng/ml. The ELISA was subsequently used to identify the presence of native IL-6 in acute phase sera of two species of delphinidae, a killer whale and a bottlenose dolphin. The application of quantitative cytokine assays as diagnostic tools for monitoring cetacean health are becoming feasible as many animals are now being trained for fluke presentation, making blood collection a routine procedure.

Interleukin-6 induces thermotolerance in cultured Caco-2 cells independent of the heat shock response.

In recent studies, induction of the heat shock response increased IL-6 production in gut mucosa in vivo and in cultured Caco-2 cells in vitro. The heat shock response is associated with increased survival of cells exposed to otherwise lethal hyperthermia, so called thermotolerance, but the role of IL-6 in the induction of thermotolerance is not known. We tested the hypothesis that treatment of cultured Caco-2 cells with IL-6 results in the development of thermotolerance. Cells were treated with human recombinant IL-6 for 1h followed by 3 h recovery in cytokine-free medium whereafter cells were exposed to heat stress (48 degrees C for 2 h). In untreated cells, the heat stress resulted in an approximately 80% cell death. In cells treated with IL-6, cell viability after heat stress was significantly improved and was doubled at an IL-6 concentration of 20 ng/ml. Treatment of the cells with other cytokines (IL-4, IL-10, IL-1beta, or TNFalpha) did not induce thermotolerance, suggesting that the effect of IL-6 may be specific for this cytokine. The induction of thermotolerance by IL-6 was blocked by an IL-6 receptor antibody, suggesting that the development of thermotolerance was receptor-mediated. Treatment of cells with IL-6 did not induce an heat shock response as suggested by unaltered heat shock protein 70 and 90 levels and unaffected heat shock factor DNA binding activity. In addition, the IL-6-induced thermotolerance was not inhibited by quercetin. The present study provides the first evidence of IL-6-induced thermotolerance and suggests that this effect of IL-6 is independent of the heat shock response.

High-dose therapy and immunomodulatory drugs in multiple myeloma

The principle of alkylating agent dose intensity, especially with melphalan-based tandem autotransplants, has been effective in increasing the rate of complete remission beyond 40% and effecting 10-year survivorship in about 40% of the three fourths of patients presenting without cytogenetic abnormalities (Total Therapy I). Further dose escalation and post-transplant consolidation therapy, as practiced with Total Therapy II, seems to further improve results in these patients, but not in those with chromosome 13 abnormalities or lactate dehydrogenase elevation. Phase III trials for post-transplant relapse indicate higher complete remission and near-complete remission rates among patients randomized to thalidomide added to dexamethasone versus dexamethasone alone. In a phase I/II study, thalidomide derivative CC-5013, with less sedative and neurotoxic effects, promoted responses in eight of 15 patients with post-transplant relapse, refractory to other salvage therapies, at dose levels of ≥ 25 mg daily. Based on a profound graft-vs-myeloma effect with allografts, mini-allotransplants were evaluated in 31 high-risk patients with cytogenetic abnormalities and prior autotransplants; all nine with responsive disease and only one prior autotransplant remain disease-free and alive. Such mini-allotransplants are now offered as consolidation after one standard autotransplant to patients with cytogenetic abnormalities. The systematic application of gene expression profiling attempts to classify multiple myeloma (MM) patients according to molecular features and to dissect the genetic basis for drug sensitivity or resistance. Given the availability of an expanding treatment armamentarium (eg, thalidomide, CC-5013, the proteasome inhibitor PS-341, farnesyltransferase inhibitors, IL-6 receptor antibody, endothelial receptor inhibitor), gene expression profiling is anticipated to help in the selection of agents with the greatest probability of activity toward individualized treatment. Careful scrutiny of gene expression will also help in the identification of unrecognized targets for therapeutic intervention. Semin Oncol 29 (suppl 17):26-33. Copyright 2002, Elsevier Science (USA). All rights reserved.